Process for the preparation of high temperature anti-friction bearing lubricants



March 4, 1958 A. J. MORWAY 2,825,694

PROCESS FOR THE PREPARATION OF HIGH TEMPERATURE ANTI-FRICTION BEARING LUBRICANTS Filed March 25, 1952 EFFEQT OF SHEARJHG On QOUISTEMY OF LUblldATIMC: GIZEA5E l l a l 0 iOO ZOO 300 400 500 600 QATE OF SHEAR. (QEcLmrzocLAL. 556914135X KY United States. Patent PROCESS FOR THE PREPARATION OF HIGH TEM- PERA'gURE ANTI-FRICTION BEARING LUBRI- CAN I Arnold J. Morway, Clarktownship, Union County, N. 5., assignor to Esso Research and Engineering Company, a corporation of Delaware Application March 25, 1952, Serial No. 278,432

' 19 Claims. (Cl. 252-332) This invention relates to lubricating grease compositions and particularly to a method for the preparation of lubricating greases. More particularly the invention relates to a novel process for the preparation of lubricating grease compositions which utilizes a technique involving the application of shearing forces without concurrent mixing to obtain maximum soap dispersion.

In the manufacture of soap thickened lubricating greases, the prior art has taught that the soap is dispersed in mineral oil by the application of heat. Upon complete melting of the soap ultimate dispersion is obtained. The actual preparation of the solid grease phase occurs during crystallization of this dispersed soap during cooling. To obtain a satisfactorily stable structure free from oil separation by this method a sufficient amount of soap must be employed since the oil in the grease structure is entrapped by interlocking grease crystals. This invention retains this prior method of dispersion of the soap by heating, along with subsequent crystallization, but in addition employs mechanical energy as a further means of soap dispersion.

After crystallization of the soap and formation of the grease structure, the relatively cool grease is subjected to the application of shearing forces without concurrent mixing, a process which, so far as the instant inventors are aware, is unknown in prior art processes. During this shearing step the soap is dispersed more eficiently and uniformly than hitherto thought possible. Advantage is taken of this more complete soap dispersion by lowering the soap concentration to obtain similar consistencies with a considerably lesser amount of soap than those obtained, or even practicable at all, in current methods of manufacture. By the employment of lower soap con:

tents, the thixotropic nature of the soap thickener can be controlled to a greater extent and, in addition, the penetration of the final product can be easily adjusted to the desired level, i. e., a grease of a desired degree of hardness can be obtained.

The gist of the instant invention lies in the technique of'applying the shearing forces upon the grease crystals. This application of shearing must occur in the absence of any concurrent or simultaneous mixing. It is postulated that the action of shear, which, by definition, involves the application of force in a plane, disperses the soap in an intimately orientated linear pattern. In addition to this linear orientation, the small bundles or fibriles of soap crystals are sheared in a plane and the resulting dispersion approaches the ultimate. If the grease formulation is not subjected to mixing which is concurrent or simultaneous, the resulting dispersion is maintained. If, however, the application of shearing force is accompanied by a simultaneous or concurrent mixing eliect the soap crystals are congregated, the orientation disappears and the resulting dispersion pattern is the one with which the art is familiar.

Rates of shear varying from about 10,000 reciprocal seconds to 500,000 or more reciprocal seconds are pre- ICC ferred in practicing the process of this invention. As will be shown later, desirable consistency increase may be obtained with a rate of shear of about 10,000 or more, and the consistency of the grease formulation may be closely controlled by controlling the rate of shear in this range. Practical application for commercial use will ordinarily dictate the use of rates of shear within the range of 100,000 to 400,000.

The process of this invention, therefore, is generally as follows:

The grease formulation is prepared by techniques which are familiar to the art. The formulation is then subjected to a shearing force without concurrent or simultaneous mixing by causing the grease to flow at high velocity and high pressure under streamlined conditions. These conditions may be obtained be equipment such as the Gaulin homogenizer, manufactured and sold by the Manton-Gaulin Manufacturing Company of Everett Massachusetts. Rolling mills, wherein the grease formulation passes through steel rollers with minute clearances, may be used. The well known Morehouse Mill, wherein the milled material passes through spinning dies at low clearances is operable. A pressure viscosimeter if operated at sufiiciently high pressures may also be used. Various other mechanical means may also. be used for the application of this shearing force, so long as there is present no concurrent mixing.

The process of the instant invention is applicable to grease compositions wherein the thickening agent is of a complex structure, that is to say, those greases which utilize as a thickening agent, or soap, a complex of two or more components may be prepared using the novel technique of the instant invention. Such complex soap greases as those prepared using rapeseed oil soaps, those greases thickened with a complex of a high molecular weight soap and a low molecular weight salt such as ace tates, furoates, acrylates, etc. are'prepared using the process of this invention. So far as is known straight fatty acidsoap greas es may not be prepared by the technique outlined above.

The instant invention is particularly applicable for the preparation of anti-friction bearing lubricants. For lubricating some types of anti-friction bearings, particularly ball bearings, the grease composition necessary to furnish the desired long and continuous lubrication at elevated temperature is a channeling type grease. That is to say, a grease which gives a low torque and low bearing temperature rise is needed since in an operating bearing of this type the grease is pushed out of the path of the rolling elements during the first few revolutions of the bearing. Thus no unnecessary power loss or heat buildup occurs in moving the grease in the bearing. This immediate channeling type grease is obtained in the prior art by high soap concentration, the grease structure beingmodified during manufacture to obtain a relatively high penetration. This grease then acts as a lubricant reservoir and as a seal to prevent entrance of dirt and other undesirable contaminants into the lubricated bearing.

The requirements of a grease of this type are as follows:

a high dropping point, usually in excess of about 350 F.; soft, unctuous characteristics; and a stable structure, as indicated by an ASTM worked penetration value of 200 to 350 mm./ 10. An excellent channeling type grease is described in detail in United States Patent No. 2,265,791, issued December 9, 1941, to Zimmer and Morway. The grease composition of this patent is prepared by thickeninga mineral lubricating oil to a grease consistency with the sodium soap of refined rapeseed oil or the acids derived therefrom. There is also present in the. finished formulation a slight excess ofsodium hydroxide. There may also be present, if desired, a small percentage of an oil-soluble petroleum sulfonate. This grease composition has been found'that the action of'both ball and roller bearings causes the high soapcontent grease compositions to beco'm'e stiff and-the desired smooth unctuous characteristic necessary for roller bearing lubrication is lost; .While'this hardening is desirable in ball bearing use, allowing ease of channeling it is undesirable in r'oller bearing service since hardening and channeling prevent satisfactory lubrication of the roller shoulders and back roller surfaces. I This is particularly noticeable in' double row bearings. p 7

These prior 'art channeling greases also tend to harden on storage because of the unbalanced grease structure, that isg the abnormally high proportion of soap to oil base. Upon standing, the grease which has been churned or stirred down to the desired consistency (penetration) tends to settle, or snap bac to the consistency which isfnorm'a'l for-"the high soap' content.

It has now been found that these undesirable tenden-' cies of channeling type lubricating greases can be removed and a grease formed by' the process of this invention which combines the following advantages:

('l) A consistency within the range of the channeling type grease, i. e., one which will satisfactorily lubricate antifriction ball bearings without undesirable loss of power, heat rise, or premature bearing failure.

'.(2) No tendency to harden'during the use in a roller bearing' because of the'high soapcontent, thus maintaining'the proper consistency to work into roller bearing crevasses and shoulders during use.

' (3) No tendency to harden during storage, since the desired consistency (penetration) is achieved with a lesser; amount of soap than was hitherto believed possible. 1

(4) An obvious economic advantage due to retention of therequired consistency for anti-frictionbearing lubrication (200-350 mm./ penetration) with approximately one-half the amount of soap as'the prior art has heretofore thought necessary.

The preparation of the prior art grease compositions for ball bearing'use is generally accomplished according to the following procedure. V

Desired amounts of refined, unblown, rapeseed oil and an equal to a'double portion of the desired mineral oil, along with a small amount of the sodium salt of a pctroleum sulfonate are charged to a fire-heated grease kettle. The kettle is equipped with an eflicient agitator or mixing blades. An amount of an aqueous caustic soda solution suflicient to give an excess of 0.3 to-0.6% sodium hydroxide, based on the finished grease, is then charged to the kettle. The mass is heated to about 250 F. until saponification is completed and the soap is dehydrated. The balance of the oil is then charged and the mass slowly heated to about 500 F., at which temperature it is completely molten. The mixture is then cooled to 200 F. with stirring; The recrystallization of the soap occurs during this cooling period and inhibitors are added then.

When using this process, it has been found that from about to soap is required to give 'a product hav ng the necessary penetration'value (20010 350 mm./ 10 after working strokes in the ASTM grease worker). As was stated above, this prior art product is an excel lent lubricant for ball bearing lubrication.

According to the instant invention,'however, the process for the preparation of these lubricating greases is' varied as follows:

Upon cooling the formulation to about 200 F. and after the addition of the additive materials, an additional 4 .7 volume ofoil is added to "the' mass. additional oil is suflicient to reduce the overall soap content to one in'the neighborhood of'6 to 18% soap. Since this product is obtained by diluting the grease with a calculated amount of mineral oil, the soap thickener is also diluted. Therefore, the resultant grease does not have the desirable grease structure but ratheris a semi-fluid product unsatisfactory as an anti-friction bearing lubricant, The total semi-fluid mass is then subjected to'highTates'of' shear in the absence of concurrent mixing. V

Attempts to prepare a lubricating grease composition from the sodium soap of unblown rapeseed oil containing only 6% to 18% soap according to conventional methods results in a grease having a structural stability far below that necessary foruse as a high temperature anti-friction bearing lubricant. By the inventive process, however, a greasecontaining only 6% to 18% soap is suitable for long satisfactory lubrication of roller bearings and is stabilized against consistency increase.

The instant invention will be more'clearly explained by reference to the following examples which are illustrative only.

EXAMPLE I.-RAPESEED OIL GREASE A grease having the following formulation was prepared as set out in detail below:

Ingredients: Weight percent Sodium soap of rapeseed oiL 20.9. Oxidation inhibitor 1.0 Metal deactivator 0.5. Stabilizer 1.0

Coastal type mineral oil sosus/zio F.) 76.6

grease was drawn, filtered and cooled in cooling pans.

The ASTM penetration results on this grease composition showing a worked penetration (60 strokesjof 286 mm./ 10.

A sample of this grease formulation was then passed:

through'a Gaulin homogenizeraf3000 p. s. i. for are}- tal of six times. This subjection of the'grease to the application of shearing forces without concurrent mixing in this equipment caused the formulation to harden due to improved soap. dispersion so that the" resulting work penetration on the treated portion was 178 mm./10.

EXAMPLE n The grease composition of Example I was diluted or,

cut back with mineral oil by mixing in the grease kettle. The blend. product was soft and fluid having no meaningful penetration. subjected to various rates of shearing in a pressure viscosimeter. In this apparatus the grease was forced through a capillary 0.4 mm. in diameter and 16 mm.

long using variable pressures up to 3000 p s. i. The flow. rate was determined by collecting the outflowing grease The rate of shear in reciprocal seconds was calculated from the standard variation 0 v for a measured time.

Poiseuilles formula:

wherein Q is the flow rate in volumes per second and R is the capillary radius. After being passed through the' I pressure viscosimeter the sample was allowed to come to room temperature (77 F.). Micro-penetrations wer'e taken after working 4 strokes in the micro-worker using a 60 mesh screen.

The data obtained are set out in Table I below.

This cut backwas,

Table I Micropenetra tion, mm./ (Worked 4 strokes in microworker) Rate of Shear Reciprocal Seconds These data appear as plots on the curve of the figure. It will be noted that the hardening effect on the grease is most pronounced at shear rates up to 100,000 reciprocal seconds. Although the application of rates of shear up to 500,000 reciprocal seconds is also effective, the

EXAMPLE III.EFFECT OF APPLICATION OF PROCESS OF INVENTION ON STANDARD GREASE INSPECTIONS Part A.-According to the procedure outlined in United States Patent 2,265,791 a grease was prepared The grease samples were also submitted to the ABBO- NLGI 204 bearing spindle life test. In this test the sample is used to lubricate a 204 bearing and the hearing is then operated at 10,000 R. P. M. at 250 F. until the bearing fails. Results are reported in hours or spindle life. The standard Norma Hoffman oxidation bomb test was also run on these grease samples. A

sample of the grease is placed in an oxygen bomb and oxygen is added until a certain pressure is attained. The bomb is then held at a constant temperature until a 5 p. s. i. pressure drop is registered and results are reported in hours.

Part B.A lubricating grease composition containing approximately 18.7% of the sodium soap of raw rapeseed oil was prepared in accordance with the process of the instant invention, that is to say, a base grease was prepared containing approximately 30% soap. It was then cooled to below the transition temperature of the soap (below about 200 F.). Sufficient mineral oil was added to result in the mass containing about 18.7% soap, based on the total product. Portion A was not homogenized, but portion B was passed through a Gaulin homogenizer at a discharge pressure of about 3,000

pounds per square inch. These grease compositions were then submitted to the inspection tests as described in part A above.

Part C.Another grease composition prepared in accordance with the process of instant invention contained approximately 12% of the sodium soap of rapeseed oil. Portion A was unhomogenized and portion B was homogenized. The samples were also submitted to the inspection tests as recorded in part A above. The inspection data on the grease samples are set out in Table II below: H

Table II.-Eflect of H omogenization at High Rates of Shear [Gamin-Homogenizer at 3000# Per Square Inch] Part A Part B Part C Portion Portion Portion Portion Portion Portion A B A B A B Composition:

Percent Soap 23. 8 18. 7 12.0 Percent Mineral Oil 76. 2 81. 3 88.0

Properties Unhomog- Homog- Unhomog- Homog- Unhomog- Homogenized enized enized enized. enized enized 10,000 R. P. M. Spindle Test (204 Ball 1, 315 1, 315-. 930 770.

Bearing Operating at 250 F., Hours).

Penetrations 77 F. mmJlO: Unwork d Worked pressure).

Wheel Bearing Test Norma-Hoffman Bomb Oxidation Test (Hours to 5 p. s. i. drop in oxygen e 6O Strokes containing 23.8% of the sodium soap of rapeseed oil and about 76.2% of mineral oil. This grease composition was divided into two portions. Portion B of the grease sample was homogenized at 3,000 pounds per square inch discharge pressure in a Gaulin homogenizer and portion A was not homogenized. The samples were submitted to the standard ASTM penetration test and the standard dropping point test. In addition, they were stored for 30 days at 210 F. and for 30 days at normal storage temperatures. They were also submitted to the ASTM wheel hearing test described in the appendix of the ASTM Handbook dated November 1948. In this test the sample is placed in a standard Ford wheel bearing and is spun at 440 R. P. M. for 6 hours at a temperature of 220 F. If any of the sample slumps or oil leaks from the bearing after the test period, the rating is Fail.

It will be noted that the grease of part A, portion A, gave excellent results in all of the inspections with the exception of the percent oil separation. Noticeable amounts of oil were separated after storage for 30 days. The worked penetration was 286 mm./ 10, which is well within the desirable limits of 200 to 350. It is also to be noted that portion B, which was subjected to homogenization, was much too hard for use as roller bearing anti-friction bearing lubricant, the worked penetration being only 173. A comparison of the greases of portions A and B of parts B and C clearly point out the advantages of the instant process. Portions A show the lack of consistency of the low soap content grease. Ho-

mogenization, however, as shown by portions B, in ad dition to giving approximately twice the yield of the I grease of part A, results in excellent smooth unctuous products without noticeable separation of oil after 30 days storage. K

7 The greases of part A, portion A, and part C, portion BfofTable'II above were'pla'ced'in a roller hearing which w'alsi operatedfor 300Qhours at a temperature of 100- 1601 F. operating range. Portion A of the grease of part A, after the test, showed a penetration of 173 which,

Glacial acetic acid 4.0 Lithium hydroxide monohydrate 6.2 Inhibitor 1.0 Coastal mineral oil (50 SUS/210 F.) 68.8

Procedure: The fish oil acids and /2 of the mineral oil were charged to a fire-heated grease kettle and heated to 150 F. with agitation. The glacial acetic acid was added followed immediately with a aqueous solution of thelithium hydroxide. The temperature was raised to 220250 F. and the balance of the mineral oil was added While slowly heating the mixture to 520 F. The inhibitor was then added and the total mixture cooled while stirring. At 200 F. additional mineral oil was charged and mixed into the grease. The finished formulation had approximately 12% soap content and on cooling gave a soft unctuous product having an ASTM worked penetration (60 strokes) of 350 mm./10.

A portion of this complex lithium soap grease was subjected to a high rate of shear without concurrent mixing by passing three times through a Gaulin homogenizer at 5,000 pounds per square inch gage. The resulting composition gave an ASTM worked penetration 60 strokes) of 167 mm./ 10. A second portion of the grease formulation was diluted with additional mineral oil until the resulting soap content was 6%. This product was soft and semi-fluid having a meaningless penetration. After 3 passes through a Gaulin homogenizer at 5,000 pounds per square inch the resulting formulation had an ASTM worked penetration (60 strokes) of 284 min/10.

These experiments indicate that the complex lithium soap greases may be advantageously prepared by the process of this invention.

EXAMPLE V.--FURFURAL GREASE A furfural grease composition having the following formulation was prepared by the procedure set out in detail below:

Ingredients: Weight percent Furfural 10.6 Hydrogenated fish oil acids 15.0 Sodium hydroxide 5.38 Oxidation inhibitor 1.0 Coastal mineral oil (40 SUS/2l-0 F.) 30.0 Coastal mineral oil (70 SUS/210 F) 38.62

Procedure: The light mineral oil and the fish oil acids were charged to a steam heated grease kettle. There was then added the sodium hydroxide in the form of a 40% aqueous solution. A temperature rise to about 100- 105 F. occurred. At this point the furfural was added atwhicb time the excess sodium hydroxide in the pres ence of the fish oil acid soap reacted with the aldehyde according to the Cannizarro reaction. This reaction was allowed to proceed for an hour with the temperature rising to about 130 F. After an hour heat was applied and the temperature raised .to about 275 F. At this point the heavy oil was added and the mixture heated with stirring to about 330 F.' At this point the oxidation inhibitor was added and the total mixture was kettle cooled with stirring.

The resulting grease composition was subjected to v shearing'forces in the absence of concurrent mixing in a G'aulinhomogenizer at varying pressures. The eflect of this treatment is set out in Table III below.

Table III Penetration, min/10. (77 F.)

Pressure (p. s. i. g.)

Worked Unworked (60 strokes) EXAMPLE VI According to the procedure of Example V above a furfural grease having the following formulation was prepared.

Ingredients: Weight percent Furfural 10.0 Hydrogenated fish oil acids 15.0 Sodium hydroxide 5.0 Oxidation inhibitor 1.0 Coastal mineral oil (80 SUS/210 F.) 34.5 Mid-Continent oil (70 SUS/2l0f F.) 34.5

Part 1.A sample of this grease composition was submitted to a Gaulin homogenizer at various pressures.

ASTM values on the samples are given in Table IV below.

Table IV Worked Penetration, mm. /10

Pressure (p. s. i. g.)

Part 2.A second sample of this grease formulation was subjected to a number of passes through the Gaulin homogenizer at 3,000 and 4,000 p. s. i. g. The ASTM worked penetration values on the greases resulting are set out in Table V below.

Table V Worked Penetration. min/10 Passes 3,000 4,000 p. s. i. g. p. s. i. g.

It will be noted from this example that the complex soap structure of the furfural type greases may also be prepared by'the process of the instant invention.

To summarize briefly this invention relates to an improved process for the preparation of lubricating grease compositions which utilizes a technique involving the application of shearing forces Without concurrent mix-' ing. The process may 'be applied to control the con sistency of a finished grease composition using a lesser amount of soap than was hitherto thought possible.

What is claimed is:

1. A method for the preparation of lubricating grease compositions which COlIlPl'liES preparing a mixture of a complex soap and a mineral oil and hardening the mixture to the desired consistency by the application of shearing forces within a range of from 10,000 to 500,000 reciprocal seconds under streamlined conditions.

2. A method for controlling the consi tency of lubricating grease compositions having a complex soap structure which comprises subjecting the composition to the action of rates of shear within the range rorn 10,000 to 500,000 reciprocal seconds under streamlined conditions.

3. A method according to claim 2 wherein the complex soap is a rapeseed oil soap.

4. A method according to claim 2 wherein the complex soap is a complex of a high molecular weight soap and a low molecular weight salt.

5. A method according to claim 2 wherein the complex soap is prepared by subjecting furfural to the Cannizzaro reaction. I

6. A method for dispersion of complex soap crystals in a lubricating oil composition to form a grease composition of a controlled consistency which comprises subjecting a mixture of soap and oil to the action of shearing forces within the range of from 100,000 to 400,000 reciprocal seconds under streamlined conditions.

7. A method according to claim 6 wherein said complex soap is rapeseed oil soap.

8. A method according to claim 6 wherein said complex soap is a complex of a high molecular weight soap and a low molecular weight salt.

9. A method according to claim 6 wherein said complex soap is prepared by subjecting furfural to the Cannizzaro reaction.

10. A method for the preparation of lubricating grease compositions having ASTM penetration values within the range of 200 to 350 mm./ 10 which comprises forming a complex soap grease having from to 50% soap, adding additional lubricating oil to reduce the overall soap content to one within the range of from 6% to 18% soap, and subjecting the mixture to the action of shearing forces in the range of from 100,000 to 400,000 reciprocal seconds under streamlined conditions.

11. A method according to claim 10 wherein said complex soap is a rapeseed oil soap.

12. A method according to claim 10 wherein said complex soap is a complex of a high molecular weight soap and a low molecular weight salt.

13. A method according to claim 10 wherein said complex soap is prepared by subjecting furfural to the Cannizzaro reaction.

14. A method for the preparation of channeling type high temperature anti-friction bearing lubricating grease compositions which comprises saponifying rapeseed oil with caustic soda in the presence of a hydrocarbon by heating in the presence of free alkali to dehydrate the material, adding additional mineral oil while stirring, heating to a temperature between about 480 F. and 520 F., cooling the mixture to a temperature below the transition temperature of the soap, adding to the cooled mixture additional mineral oil to substantially reduce the soap content of the mixture and subjecting the total mixture to shearing action under streamlined conditions to obtain the final product.

15. A method for the preparation of channeling type high temperature anti-friction bearing lubricating grease composition containing from about 10% to about 15% soap which comprises saponifying raw rapeseed oil with caustic soda in the presence of a hydrocarbon oil by heating in the presence of free alkali to dehydrate the material, adding additional mineral oil while stirring, heating to a temperature or about 480 F. to 520 F., cooling the mixture to obtain a composition containing approximately 20% to 30% soap, adding to the cooled mixture additional mineral oil and subjecting the total mixture to an action of shearing forces in the range of from about 100,000 to about 500,000 reciprocal seconds under conditions of streamlined flow to obtain a final product.

16. A process according to claim 15 wherein said line-flow shearing force is applied by subjecting the total mixture to the action of a pressure viscosimeter.

17. The method of preparation of channeling type high temperature anti-friction bearing grease lubricating composition which comprises heating a mixture of mineral oil, a small amount of an oil-soluble sodium sulfonatc and sufficient rapeseed oil to give a final product containing 20% to 30% soap, adding aqueous sodium hydroxide in a slight excess over that necessary to completely saponity the rapeseed oil, further heating the rapeseed oil to dehydrate the mixture, adding additional mineral oil and continuing the heating to about 480 F. to 520 F. with stirring, cooling the resulting composition to a temperature below about 275 F., adding an additional amount of mineral oil sufiicient to result in a grease composition containing about 10% to about 15% soap and subjecting the mixture to the action of shearing forces under streamlined conditions to obtain a smooth unctuous grease composition having an ASTM worked penetration of at least 275 mm./ 10.

18. A method according to claim 17 wherein the shearing forces are within the range of from 10,000 to 500,000 reciprocal seconds.

19. A method according to claim 17 wherein the shearing forces are within the range of from 150,000 to 250,000 reciprocal seconds.

References Cited in the file of this patent UNITED STATES PATENTS 2,108,672 Kaufman Feb. 15, 1938 2,265,791 Zimmer et a1. Dec. 9, 1941 2,318,668 Calkins May 11, 1943 2,383,906 Zimmer et a1. Aug. 28, 1945 2,431,453 Beerbower et a1 Nov. 25, 1947 2,433,636 Thurman Dec. 30, 1947 2,459,483 Zimmer et a1. Jan. 18, 1949 2,461,276 Hetherington Feb. 8, 1949 2,478,917 Hain Aug. 16, 1949 2,503,676 Marusov Apr. 11, 1950 2,516,137 Morway et a1. July 25, 1950 2,542,159 Stevens Feb. 20, 1951 2,588,556 Moore et al. Mar. 11, 1952 2,599,343 Morway et al. June 3, 1952 2,610,947 Morway Sept. 16, 1952 2,626,241 Sparks et al. Jan. 20, 1953 2,704,363 Armstrong Mar. 15, 1955 2,713,790 Barber et a1. July 26, 1955 FOREIGN PATENTS 18,249 Great Britain Aug. 19, 1902 22,875 Great Britain Nov. 15, 1903 22,941 Great Britain Nov. 8, 1905 OTHER REFERENCES Design of Emulsifying Machines, Robert Johnson found in text of Emulsion Technology, pages 88-118, 2nd edition, Chem. Pub. Co., Brooklyn, N. Y. 

17. THE METHOD OF PREPARATION OF CHANNELING TYPE HIGH TEMPERATURE ANTI-FRICTION BEARING GREASE LUBRICATING COMPOSITION WHICH COMPRISES HEATING A MIXTURE OF MINERAL OIL, A SMALL AMOUNT OF AN OIL-SOLUBLE SODIUM SULFONATE AND SUFFICIENT RAPESEED OIL TO GIVE A FINAL PRODUCT CONTAINING 20% TO 30% SOAP, ADDING AQUEOUS SODIUM HYDROXIDE IN A SLIGHT EXCESS OVER THAT NECESSARY TO COMPLETELY SAPONIFY THE RAPESEED OIL, FURTHER HEATING THE RAPESEED OIL TO DEHYDRATE THE MIXTURE, ADDING ADDITIONAL MINERAL OIL AND CONTINUING THE HEATING TO ABOUT 480*F. TO 520*F. WITH STIRRING, COOLING THE RESULTING COMPOSITION TO A TEMPERATURE BELOW ABOUT 275*F., ADDING AN ADDITIONAL AMOUNT OF MINERAL OIL SUFFICIENT TO RESULT IN A GREASE COMPOSITION CONTAINING ABOUT 10% TO ABOUT 15% SOAP AND SUBJECTING THE MIXTURE TO THE ACTION OF SHEARING FORCES UNDER STREAMLINED CONDITIONS TO OBTAIN A SMOOTH UNCTUOUS GREASE COMPOSITION HAVING AN ASTM WORKED PENETRATION OF AT LEAST 275 MM./10. 